Retinal ganglion cell function after repeated intravitreal injections of ranibizumab in patients with age-related macular degeneration

Electrophysiological Evaluation of Macular Photoreceptor Functions in Patients with Choroidal Neovascular Membranes

PURPOSE

To evaluate changes in cone functions using light-adapted (LA) 30 Hz flicker and LA 3.0 electroretinography (ERG) in intravitreal ranibizumab (IVR)-treated naïve neovascular age-related macular degeneration (nAMD) patients.

MATERIALS AND METHODS

This retrospective interventional study reviewed the medical records of 32 nAMD patients (32 eyes) who received monthly IVR between January 2019 and January 2021. A comprehensive ophthalmic examination, including best-corrected visual acuity (BCVA) testing and slit-lamp biomicroscopy, was performed as part of their clinical care, followed by LA 30 Hz flicker and LA 3.0 ERGs, optical coherence tomography, and fundus fluorescein angiography. All measurements were taken before IVR (baseline), as well as at months 6 and 12 later. Treatment was resumed for up to 12 months if recurrence occurred.

RESULTS

Compared to baseline, visual acuity improved significantly at months 6 and 12, respectively, coinciding with a significant decrease in central macular thickness (p < 0.05 for all). LA 30 Hz flicker ERG b-wave amplitude decreased significantly between baseline and months 6 and 12, respectively (p < 0.05 for both). There were no significant changes in LA 3.0 ERG a- and b-wave amplitudes between baseline and month 6 (p > 0.05 for both), but a significant decrease existed between baseline and month 12 (p < 0.05 for both). While LA 3.0 ERG a-wave implicit time increased significantly (p < 0.05 for both) between baseline and months 6 and 12, respectively, b-wave implicit time did not (p > 0.05 for both). Also, LA 30 Hz flicker ERG b-wave implicit times did not differ significantly between baseline and months 6 and 12, respectively (p > 0.05, for both).

CONCLUSIONS

IVR was associated with long-term electrophysiological changes in cone functions, as measured by LA 30 Hz flicker and LA 3.0 ERGs.

Morphological and Functional Assessment of the Optic Nerve Head and Retinal Ganglion Cells in Dry vs Chronically Treated Wet Age-Related Macular Degeneration

Purpose

The aim of the study comprised the anatomical and functional assessment of the optic nerves and macular ganglion cells in the population of patients with unilateral wet age-related macular degeneration (wAMD) and comparison of its results to those obtained from the fellow eye with non-advanced dry age-related macular degeneration (dAMD). Furthermore, we aimed to determine if the number of administered injections contributed to the potential differences between the examined eyes.

Methods

The study was based on 104 eyes of 52 patients in a cross-sectional study. The eyes with chronically treated wAMD were the main subject of the study, while fellow eyes affected with non-advanced dAMD served as the control group. Primary morphological outcomes comprised differences in peripapillary retinal nerve fiber layer (RNFL) and GCC layers between the studied groups (treated and control). In turn, primary functional outcomes included differences in implicit times and amplitudes of the P100 wave of pattern visual evoked potentials (PVEP) and N95 wave of pattern electroretinogram (PERG) between treated and control groups.

Results

We did not find any differences in total RNFL thickness between wAMD and dAMD groups. The number of injections only affected the RNFL in the nasal quadrant of the optic disc (p = 0.023). We did not find any differences regarding GCL thickness in both groups. In the study group, a longer implicit time of the P100 of PVEP (p = 0.014) and a shorter amplitude of the P50-N95 wave of PERG (p = 0.005) were detected. The total number of injections had no significant effect on these two values.

Conclusion

We detected worse functional parameters of the optic nerve and retinal ganglion cells in eyes with wAMD, with lack of significant differences in anatomical (RNFL, GCL) parameters compared to the control group. However, the number of injections did not contribute to the differences found.

Preventive Effects against Retinal Degeneration by Centella asiatica Extract (CA-HE50) and Asiaticoside through Apoptosis Suppression by the Nrf2/HO-1 Signaling Pathway

Age-related macular degeneration (AMD) is caused by the chronic and gradual oxidative degeneration of the retina. Unfortunately, the general purpose of current treatments is to slow AMD progression, as the retina cannot be restored to its pre-AMD condition. We aimed to identify natural products that can be potential treatments that prevent AMD and can delay the development of late-AMD and selected Centella asiatica extract (CA-HE50), which shows excellent efficacy in cytoprotection. In animal experiments using N-methyl-N-nitrosourea (MNU), CA-HE50 dramatically increased the thickness of photoreceptors and the outer nuclear layer (ONL) and the number of nuclei in the ONL (p < 0.05). Using retinal epithelial ARPE-19 cells showed that CA-HE50 inhibited apoptosis through inhibition of the intrinsic apoptosis signaling pathway and cell cycle regulation (p < 0.05). The anti-apoptotic efficacy was confirmed to be due to activation of the Nrf2/HO-1 antioxidation pathway (p < 0.05). These results were also observed with asiaticoside, a functional substance of CA-HE50. In addition, the accumulation of oxidized-N-retinylidene-N-retinylethanolamine (A2E), which induces AMD, was inhibited by CA-HE50, resulting in increased ARPE-19 cell viability (p < 0.05). This study demonstrates that CA-HE50 is worth further research and human application tests, to develop it as a raw material for treatment or dietary supplement for the prevention of AMD.

Lentiviral delivery of co-packaged Cas9 mRNA and a Vegfa-targeting guide RNA prevents wet age-related macular degeneration in mice

Therapeutic genome editing requires effective and targeted delivery methods. The delivery of Cas9 mRNA using adeno-associated viruses has led to potent in vivo therapeutic efficacy, but can cause sustained Cas9 expression, anti-Cas9 immune responses and off-target edits. Lentiviral vectors have been engineered to deliver nucleases that are expressed transiently, but in vivo evidence of their biomedical efficacy is lacking. Here, we show that the lentiviral codelivery of Streptococcus pyogenes Cas9 mRNA and expression cassettes that encode a guide RNA that targets vascular endothelial growth factor A (Vegfa) is efficacious in a mouse model of wet age-related macular degeneration induced by Vegfa. A single subretinal injection of engineered lentiviruses knocked out 44% of Vegfa in retinal pigment epithelium and reduced the area of choroidal neovascularization by 63% without inducing off-target edits or anti-Cas9 immune responses. Engineered lentiviruses for the transient expression of nucleases may form the basis of new treatments for retinal neovascular diseases.

Comparisons of photopic negative responses elicited by different conditions from glaucomatous eyes

PURPOSE

To compare the clinical significance of the photopic negative response (PhNRs) elicited by different stimuli from glaucomatous eyes.

STUDY DESIGN

Single-center observational study METHOD: Eighty-four eyes of 84 patients with open angle glaucoma (OAG) and 40 eyes of 40 normal subjects were studied. Cone electroretinograms (ERGs) were elicited by white stimuli on a white background (W/W) or red stimuli on a blue background (R/B). The luminance of the stimuli was 0.5, 1.0, 2.0 or 3.0 cd-s/m², and of the background light was 10 cd/m². The first and second troughs of the ERGs that appeared following the b-wave were designated as PhNR1 and PhNR2, respectively. The thickness of the circumpapillary retinal nerve fiber layer (cpRNFL) was measured by spectral-domain optical coherence tomography. The mean deviation (MD) was determined by standard automated perimetry. The area under the receiver operating characteristic curves (AUCs) was created to determine the diagnostic ability of the PhNRs elicited by the different stimulus conditions.

RESULTS

The correlation coefficients of the amplitudes of the PhNR1 elicited by W/W stimuli to the MDs and cpRNFL thickness were generally stronger, and the regression lines steeper than for the amplitudes of the PhNR1 elicited by R/B stimuli. In contrast, the correlation coefficients of the amplitudes of the PhNR2 elicited by R/B stimuli to the MDs and cpRNFL thickness were generally stronger, and the regression lines were steeper than the amplitudes of the PhNR2 elicited by W/W stimuli. With both types of stimuli, the slopes of the regression lines became steeper when the ERG recorded with higher stimulus intensities. The AUCs were significantly larger for the PhNR2 elicited by the R/B stimuli at 3.0 cd-s/m² than for PhNR1 and PhNR2 elicited by W/W stimuli at the same intensity when the PhNRs were used for diagnosing advanced glaucoma.

CONCLUSION

The PhNR1 and PhNR2 elicited by the W/W and R/B stimuli are suitable measures to assess the function of the RGCs in eyes with OAG. The PhNR2 elicited by R/B stimuli at higher stimulus intensities is most effective in detecting functional and structural changes of the RGCs with the highest diagnostic capacity in discriminating advanced glaucoma.

Correlation between macular structure and function in patients with age-related macular degeneration treated with intravitreal ranibizumab: 12-month-results

PURPOSE

To determine the significance of the correlation between optical coherence tomographic (OCT) findings and focal macular electroretinograms (fmERG) at 12 months after beginning intravitreal injections of ranibizumab (IVR) in eyes with age-related macular degeneration (AMD).

STUDY DESIGN

Prospective, clinical study.

METHOD

We studied 28 eyes of 28 patients with AMD treated with IVR at monthly intervals for the initial three months. Additional IVR was given according to a pro re nata (PRN) regimen. OCT and fmERGs were performed preoperatively and at 3 and 12 months postoperatively. The fmERGs were elicited by a 15° white stimulus spot centered on the fovea. The thickness of the inner, middle, and outer layers of the retina and also of the serous retinal detachment (SRD) and pigment epithelial detachment (PED) in the horizontal and vertical meridians at 1.2 mm from the fovea (parafoveal) were measured in the OCT images.

RESULTS

The b-wave amplitude at 12 months was significantly correlated with the thicknesses of the outer retinal layer, SRD, and PED (P=0.001-0.02). Multiple regression analyses showed that the outer retinal layer thickness was an independent determinant (P= 0.0001). The changes in the b-wave amplitude between the baseline and 12 months were significantly correlated with the changes in the SRD thickness (P=0.006). The changes in the b-wave amplitude during the PRN period were significantly correlated with the changes in the PED thickness (P=0.02).

CONCLUSIONS

At 12 months after beginning treatment, the reduction in the SRD thickness affects macular function recovery. As recurrences of the PED can occur during the PRN period, control of the PED is necessary to obtain good macular function for the long term.

Preclinical Evaluation of ADVM-022, a Novel Gene Therapy Approach to Treating Wet Age-Related Macular Degeneration

Inhibition of vascular endothelial growth factor, a key contributor to the choroidal neovascularization associated with wet age-related macular degeneration, is the mode of action of several approved therapies, including aflibercept, which requires frequent intravitreal injections to provide clinical benefit. Lack of compliance with the dosing schedule may result in recurrence of active wet macular degeneration, leading to irreversible vision impairment. Gene therapy providing sustained anti-vascular endothelial growth factor levels in the retina following a single injection could drastically reduce the treatment burden and improve visual outcomes. ADVM-022, an adeno-associated virus vector encoding aflibercept, is optimized for intravitreal delivery and strong protein expression. Here, we report the long-term expression and efficacy of ADVM-022-derived aflibercept in a laser-induced choroidal neovascularization model in non-human primates. Intravitreal administration of ADVM-022 was well tolerated and resulted in sustained aflibercept levels. In addition, ADVM-022 administration 13 months before lasering prevented the occurrence of clinically relevant choroidal neovascularization lesions, similar to animals that received a bolus of intravitreal aflibercept (standard of care) at the time of lesioning. These results demonstrate that a single intravitreal administration of ADVM-022 may provide a safe and effective long-term treatment option for wet macular degeneration and may ultimately improve patients’ visual outcomes.

The Effect of Ranibizumab on Normal Neurosensory Retina in the Eyes of Patients with Exudative Age Related Macular Degeneration

Background:

Anti-vascular endothelial growth factors have become the mainstay treatment for neovascular age related macular degeneration. Prolonged suppression of vascular endothelial growth factor raises concerns as it may result in harmful effects on retina.

Objective:

The purpose of this retrospective chart review is to evaluate the 1-year effect of treatment with intravitreal injections of ranibizumab on normal neurosensory retinal tissue of patients with exudative age related macular degeneration using the Optical Coherence Tomography (OCT).

Method:

The study included sixty five eyes of 62 patients (32 male and 30 female; mean age 74.97±8.5 years) with exudative age related macular degeneration treated with intravitreal injections of ranibizumab with a pro re nata treatment regimen over a period of 1 year. The MM5 thickness maps acquired with the Optovue RTVue-100 Fourier-domain OCT at baseline, at 3 months, after the 3 loading doses of ranibizumab, and at the 1 year follow-up visit were used for analysis. Changes of inner and outer retinal thickness in four selected points of normal retina on the MM5 scan were evaluated.

Results:

The patients received a mean of 6.4 ± 1.8 (median 6, range 3-11) intravitreal injections of ranibizumab over a period of 12 months. No significant change was observed in inner and outer retinal thickness at pre-selected spots of normal retina during the first year of intravitreal administration of ranibizumab.

Conclusion:

One year treatment with ranibizumab on an individualized, according to need dosing regimen does not seem to induce any detectable structural damage in the unaffected, normal retina.

Cross-sectional pupillographic evaluation of relative afferent pupillary defect in age-related macular degeneration

To evaluate, using pupillography, the difference between eyes affected by age-related macular degeneration and their contralateral normal eyes with regard to the mean relative afferent pupillary defect (RAPD) score. Also, to ascertain any correlations between this difference in RAPD score and differences in visual acuity or age-related macular degeneration (AMD) dimensions. Measurements were made using the RAPDx pupillographer (Konan Medical, Nishinomiya, Japan), which analyzes pupil response to light stimulation. Both best corrected visual acuity (converted to logMAR) and greatest linear dimension (GLD; calculated on the basis of fluorescence angiography images) were measured. The correlations between RAPD difference and logMAR difference, and GLD difference were then analyzed. The study included 32 patients (18 men, 14 women; mean age = 74.8 ± 9.7 years) who had AMD in 1 eye and a normal fundus in the contralateral eye. Mean resting pupil diameter, mean latency onset of constriction, mean velocity of constriction, and recovery were not significantly different in AMD eyes compared with normal eyes. The mean amplitude of constriction was smaller (P = 0.028), and the mean latency of maximum constriction was shorter (P = 0.0013) in AMD eyes than in normal eyes. Regarding RAPD scores, there was a significant correlation between visual acuity difference and RAPD score differences of both amplitude (P < 0.001, r = 0.53) and latency (P = 0.034, r = 0.33). GLD difference was also significantly correlated with differences in both amplitude (P = 0.021, r = 0.36) and latency (P = 0.033, r = 0.33) scores. RAPD outcomes were correlated with visual acuity and AMD dimension. Automated pupillography may be a useful tool in monitoring the progression of AMD and assessing changes in retinal function that result from novel interventions.

Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab

Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD. Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection. Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P = 0.031) and a reduction of mean foveal (P = 0.001) and macular thickness (P = 0.001) were observed. Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex.

Structures affecting recovery of macular function in patients with age-related macular degeneration after intravitreal ranibizumab

PURPOSE

To determine the retinal structures affecting the recovery of macular function in patients with exudative age-related macular degeneration (AMD) treated with intravitreal ranibizumab (IVR).

METHOD

Thirty eyes of 30 patients with exudative AMD who were treated with IVR at monthly intervals for 3 months were studied. Focal macular electroretinograms (fmERGs) and spectral-domain optical coherence tomography (SD-OCT) were performed before and 3 months after beginning the IVR injections. The fmERGs were elicited by a 15° white stimulus spot centered on the fovea. The thickness of different retinal layers, presence of a serous retinal detachment (SRD), and presence of a pigment epithelial detachment (PED) at the fovea was determined in the SD-OCT images. Measurements were made of the inner, middle, and outer layers of the retina and also of the SRD and PED in the horizontal and vertical meridians at 1.2 mm from the fovea (parafoveal regions). The significance of the correlations between these structural parameters and the a-wave amplitude of the fmERG was determined.

RESULTS

There was no significant correlation between the structural parameters of the fovea and the a-wave amplitude. In the parafoveal regions, the thickness of the outer retinal layer was significantly correlated with an increase of the a-wave amplitude (R = 0.56, P = 0.001). In addition, the SRD thickness was negatively and significantly correlated with the a-wave amplitude (R = -0.54, P = 0.002). The change in the parafoveal SRD thickness after IVRs was the only independent determinant of recovery of the a-wave amplitude after the treatments (P < 0.05).

CONCLUSIONS

The macular function measured by the fmERGs was determined by the parafoveal outer layer and SRD thickness in patients with exudative AMD. Of these, changes in the SRD thickness by IVRs most strongly affected the recovery of macular function.

Ganglion Cell Complex Evaluation in Exudative Age-Related Macular Degeneration after Repeated Intravitreal Injections of Ranibizumab

Purpose. To detect the effects of intravitreal ranibizumab injections on GCC in patients with wet AMD.Methods. 32 wet AMD eyes were selected and submitted at three ranibizumab injections. RTVue-OCT GCC and MM5 protocol were performed before treatment and twenty days after each injection.Results. At baseline mean GCC thickness was 93.9 ± 18.5 μm. Twenty days after each intravitreal injection it was, respectively, 85.8 ± 10.1, 86.5 ± 9.3, and 91.1 ± 11.5 μm, without statistical significance. A significant improvement in visual acuity (P= 0.031) and a reduction of mean foveal (P= 0.001) and macular thickness (P= 0.001) were observed.Conclusion. The clinical results confirm therapeutic efficacy of intravitreal injections of ranibizumab in wet AMD. A contemporary not statistically significant reduction of GCC thickness suggests that the loading phase of ranibizumab does not have any toxic effects on ganglion cell complex.

Inner retinal layer comparisons of eyes with exudative age-related macular degeneration and eyes with age-related macular degeneration and glaucoma

BACKGROUND

The incidence of glaucoma increases with age, as does age-related macular degeneration (AMD), with the reported incidence of glaucoma among AMD subjects being 5.4 %. Optical coherence tomography (OCT) can detect glaucomatous changes in the inner retina with high sensitivity. The purpose of this study was to compare ganglion cell complex (GCC) parameters and the thickness of the peripapillary retinal nerve fiber layer (RNFL) in normal eyes to that observed in eyes with age-related macular degeneration (AMD) and eyes with both AMD and glaucoma.

METHODS

The GCC components [GCC thickness, focal loss volume (FLV), and global loss volume (GLV)] and peripapillary RNFL thickness were measured using RTVue spectral-domain OCT (SD-OCT). The GCC and RNFL parameters of normal eyes, AMD eyes treated with different types of therapy, and AMD eyes with and without glaucoma were evaluated using nonparametric tests. Univariate and multivariate analyses were used to determine whether the GCC and RNFL parameters could be used to differentiate AMD eyes with glaucoma from those without glaucoma.

RESULTS

Seventy-one normal eyes, 120 eyes with AMD, and 23 eyes with AMD and glaucoma were studied. The values of all GCC components were significantly different in the normal eyes from those observed in the eyes with AMD, except for the RNFL thicknesses. The GCC and RNFL parameters were not significantly different between the eyes receiving different types of therapy among the AMD groups. The RNFL thickness was significantly correlated with glaucoma diagnosis in AMD eyes.

CONCLUSIONS

These findings indicate that there is damage to the inner retinal layers in eyes with AMD. The RNFL thickness can be a useful parameter for differentiating eyes with AMD from eyes with both AMD and glaucoma.